ibotpeaches/apktool

Apktool is a reverse engineering tool for Android APK files. An APK (Android Package) is the file format used to distribute and install Android apps, essentially a compressed archive containing the app's code, resources, and configuration. Apktool lets you take a compiled APK and extract its contents back into a human-readable form. Specifically, it decodes the app's resources (images, layout files, strings) and converts the compiled bytecode back into a readable intermediate format called Smali, which is close to the underlying Android bytecode. Once decoded, you can inspect or modify the app, then repackage it into a new APK. Common legitimate uses include translating apps into other languages, investigating how an app behaves for security research, adapting apps to work on custom platforms, or debugging applications. The project explicitly states it is not intended for piracy or other illegal uses. You would use Apktool when you need to examine the internals of an Android app you do not have the source code for, or when you want to modify resources like strings and images in an existing APK. The tech stack is Java.